Not all platforms that NetBSD runs on support fdisk. Besides, until
recently you were limited to four fdisk partitions, which was a
nuisance for NetBSD.
Indeed, very few platforms natively use BIOS-style labels. A key
point is that disk labels have to match the hardware/PROMs native
expectations for finding and booting a kernel.
The right answer is a program that can read fdisk labels and generate
NetBSD label data. It shouldn't be too hard to write, either.
You don't even have to write it - mbrlabel(8).
--
Greg Troxel <gdt@ir.bbn.com>